Anterior Knee Pain and Patellar Instability pdf

Anterior Knee Pain and Patellar Instability

Vicente Sanchis-Alfonso (Ed)

Anterior Knee Pain
and Patellar Instability
With 240 Figures
including 108 Color Plates

Vicente Sanchis-Alfonso, MD, PhD (Member of the
International Patellofemoral Study Group/Member
of the ACL Study Group)
Department of Orthopaedic Surgery
Hospital Arnau de Vilanova
Valencia
Spain

British Library Cataloguing in Publication Data
Anterior knee pain and patellar instability
1. Patellofemoral joint - Dislocation 2. Patella Dislocation 3. Knee - Diseases 4. Knee - Wounds and injuries
5. Knee - Surgery 6. Pain - Physiological aspects

I. Sanchis-Alfonso, Vicente
617.5′82
ISBN-10: 1846280036
Library of Congress Control Number: 2005925983
ISBN-10: 1-84628-003-6
ISBN-13: 978-1-84628-003-0

e-ISBN 1-84628-143-1

Printed on acid-free paper
© Springer-Verlag London Limited 2006
First published in 2003 as Dolor anterior de rodilla e inestabilidad rotuliana en el paciente joven. This Englishlanguage edition published by arrangement with Editorial Médica Panamericana S.A.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted
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To my father. In memoriam (†)

Foreword

Anterior knee pain is one of the really big problems in my specialty, sports orthopaedic
surgery, but also in all other types of orthopaedic surgery. Many years ago Sakkari Orava
in Finland showed that among some 1311 Finnish runners, anterior knee pain was the
second most common complaint. In young school girls around 15 years of age, anterior
knee pain is a common complaint. In ballet classes of the same age, as much as 60-70%
of the students complain of anterior knee pain. It is therefore an excellent idea of Dr.

Sanchis-Alfonso to publish a book about anterior knee pain and patello-femoral instability in the active young.
He has been able to gather a group of extremely talented experts to help him write this
book. I am particularly happy that he has devoted so much space to the non-operative
treatment of anterior knee pain. During my active years as a knee surgeon, one of my
worst problems was young girls referred to me for surgery of anterior knee pain. Girls
that had already had 8-12 surgeries for their knee problem — surgeries that had rendered them more and more incapacitated after each operation. They now came to me for
another operation. In all these cases, I referred them to our pain clinic for careful analysis, and pain treatment followed by physical therapy. All recovered but had been the victims of lots of unnecessary knee surgery before they came to me.
I am also happy that Suzanne Werner in her chapter refers to our study on the personality of these anterior knee patients. She found that the patients differ from a normal
control group of the same age. I think this is very important to keep in mind when you
treat young patients with anterior knee pain.
In my mind physical therapy should always be the first choice of treatment. Not until
this treatment has completely failed and a pain clinic recommends surgery, do I think
surgery should be considered.
In patello-femoral instability the situation is different. When young patients suffer
from frank dislocations of the patella, surgery should be considered. From my many
years of treating these types of patients, I recommend that the patients undergo an
arthroscopy before any attempts to treat the instability begin. The reason is that I have
seen so many cases with normal X-rays that have 10-15 loose bodies in their knees. If
these pieces consist of just cartilage, they cannot be seen on X-ray. When a dislocated
patella jumps back, it often hits the lateral femoral condyle with considerable force.

Small cartilage pieces are blasted away as well from femur as from the patella. If they are
overlooked they will eventually lead to blockings of the knee in the future.
The role of the medial patello-femoral ligament can also not be overstressed. When I
was taught to operate on these cases, this ligament was not even known.
I also feel that when patellar instability is going to be operated on, it is extremely
important that the surgeon carefully controls in what direction the instability takes
place. All instability is not in lateral direction. Some patellae have medial instability. If
someone performs a routine lateral release in a case of medial instability, he will end up

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Foreword

having to repair the lateral retinaculum in order to treat the medial dislocation that
eventually occurs. Hughston and also Teitge have warned against this in the past.
It is a pleasure for me to recommend this excellent textbook by Dr.Vicente SanchisAlfonso.
Ejnar Eriksson, MD, PhD
Professor Emeritus of Sports Medicine

Karolinska Institute, Stockholm, Sweden

Preface

This book reflects my deep interest in the pathology of the knee, particularly that of the
extensor mechanism, and to bring to the fore the great importance I give to the concept
of subspecialization, this being the only way to confront the deterioration and mediocrity of our speciality, Orthopaedic Surgery; and to provide our patients with better care.
In line with the concept of subspecialization, this book necessarily required the participation of various authors. In spite of this, I do not think there is a lack of cohesion
between the chapters. Now, there are certain variations in form, but not in basic content,
regarding some topics dealt with by different authors. It is thus evident that a few
aspects remain unclear, and the controversy continues.
With this work, we draw upon the most common pathology of the knee, even though
the most neglected, the least known and the most problematic (Black Hole of
Orthopaedics). To begin with, the terminology is confusing (The Tower of Babel). Our
knowledge of its etiopathogeny is also limited, with the consequence that its treatment
is of the most complex among the different pathologies of the knee. On the other hand,
we also face the problem of frequent and serious diagnostic errors that can lead to
unnecessary interventions. The following data reflect this problem: 11% of patients in
my series underwent unnecessary arthroscopy, and 10% were referred to a psychiatrist
by physicians who had previously been consulted.

Unlike other publications, this work gives great weight to etiopathogeny; the latest
theories are presented regarding the pathogeny of anterior knee pain and patellar instability, although in an eminently clinical and practical manner. In agreement with John
Hunter, I think that to know the effects of an illness is to know very little; to know the
cause of the effects is what is important. Nonetheless, we forget neither the diagnostic
methods nor therapeutic alternatives, both surgical and non-surgical, emphasizing minimal intervention and non-surgical methods. Similarly, much importance is given to
anterior knee pain following ACL reconstruction. Further, the participation of diverse
specialists (orthopaedic surgeons, physiotherapists, radiologists, biologists, pathologists, bioengineers, and plastic surgeons), that is, their multidisciplinary approach,
assures us of a wider vision of this pathology. The second part of this monograph is
given over to discussion of complex clinical cases that are presented. I reckon we learn
far more from our own errors, and those of other specialists, than from our successes.
We deal with oft-operated patients with sequelae due to interventions, adequate or otherwise, but which have become complicated. The diagnoses arrived at are explained, and
how the cases were resolved (“Good results come from experience, experience from bad
results”, Professor Erwin Morscher).
Nowadays we are plunged into the “Bone and Joint Decade” (2000-2010). The WHO’s
declared aim is to make people aware of the great incidence of musculoskeletal pathology and to reduce both economic and social costs. These same goals I have laid out in
this book. Firstly, we are mindful of the soaring incidence of this pathology, and the
impact on young people, athletes, workers, and the economy. Secondly, to improve
prevention and diagnosis in order to reduce the economic and social costs of this

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Preface

pathology. The final objective is to improve health care in these patients. This, rather
than being an objective, should point the way forward.
Anterior Knee Pain and Patellar Instability is addressed to orthopaedic surgeons
(both general and those specialized in knee surgery), specialists in sports medicine and
physiotherapists.
We feel thus that with this approach, this monograph will fill an important gap in the
literature of pathology of the extensor mechanism of the knee. However, we do not
intend to substitute any work on patellofemoral pathology, but rather to complement
existing literature (“All in all, you’re just another brick in the wall”, Pink Floyd, The
Wall). Although the information contained herein will evidently require future revision,
it serves as an authoritative reference on one of the most problematic entities current in
pathology of the knee. We trust that the reader will find the work useful, and consequently, be indirectly valuable for patients.
Vicente Sanchis-Alfonso, MD, PhD
Valencia, Spain
February 2005

Acknowledgments

I wish to express my sincere gratitude to my friend and colleague, Dr Donald Fithian,
who I met in 1992 during my stay in San Diego CA, for all I learned, together with his
help, for which I will be forever grateful; to Professor Ejnar Eriksson for writing the foreword; to Dr Scott Dye for writing the epilogue, to Nicolás Fernández for his valuable
photographic work, and also to Stan Perkins for his inestimable collaboration, without
whom I would not have managed to realize a considerable part of my projects. My gratitude also goes out to all members of the International Patellofemoral Study Group for
their constant encouragement and inspiration.
Further, I have had the privilege and honor to count on the participation of outstanding specialists who have lent prestige to this monograph. I thank all of them for their
time, effort, dedication, amiability, as well as for the excellent quality of their contributing chapters. All have demonstrated generosity in sharing their great clinical experience
in clear and concise form. I am in debt to you all. Personally, and on behalf of those
patients who will undoubtedly benefit from this work, thank you.
Last but not least, I am extremely grateful to both Springer in London for the confidence shown in this project, and to Barbara Chernow and her team for completing
this project with excellence from the time the cover is opened until the final chapter is
presented.
Vicente Sanchis-Alfonso, MD, PhD

xi

Contents

Foreword
Ejnar Eriksson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Preface
Vicente Sanchis-Alfonso . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ix

Acknowledgments
Vicente Sanchis-Alfonso . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xi

Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii

Section I
Etiopathogenic Bases and Therapeutic Implications
1 Background: Patellofemoral Malalignment versus Tissue Homeostasis.
Myths and Truths about Patellofemoral Disease

Vicente Sanchis-Alfonso . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

2 Pathogenesis of Anterior Knee Pain and Patellar Instability in the Active Young.
What Have we Learned from Realignment Surgery?
Vicente Sanchis-Alfonso, Fermín Ordoño,
Alfredo Subías-López, and Carmen Monserrat . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3 Neuroanatomical Bases for Anterior Knee Pain in the Young Patient:
“Neural Model”
Vicente Sanchis-Alfonso, Esther Roselló-Sastre,
Juan Saus-Mas, and Fernando Revert-Ros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4 Biomechanical Bases for Anterior Knee Pain and Patellar
Instability in the Young Patient
Vicente Sanchis-Alfonso, Jaime M. Prat-Pastor,
Carlos M. Atienza-Vicente, Carlos Puig-Abbs,
and Mario Comín-Clavijo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5 Anatomy of Patellar Dislocation
Donald C. Fithian and Eiki Nomura . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
6 Evaluation of the Patient with Anterior Knee Pain

and Patellar Instability
Vicente Sanchis-Alfonso, Carlos Puig-Abbs,
and Vicente Martínez-Sanjuan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

xiii

xiv

Contents

7 Uncommon Causes of Anterior Knee Pain
Vicente Sanchis-Alfonso, Erik Montesinos-Berry,
and Francisco Aparisi-Rodriguez . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
8 Risk Factors and Prevention of Anterior Knee Pain
Erik Witvrouw, Damien Van Tiggelen, and Tine Willems . . . . . . . . . . . . . . . . . . . 135
9 Conservative Treatment of Athletes with Anterior Knee Pain.
Science: Classical and New Ideas
Suzanne Werner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
10 Conservative Management of Anterior Knee Pain:
The McConnell Program
Jenny McConnell and Kim Bennell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
11 Skeletal Malalignment and Anterior Knee Pain: Rationale,
Diagnosis, and Management
Robert A. Teitge and Roger Torga-Spak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
12 Treatment of Symptomatic Deep Cartilage Defects of the Patella
and Trochlea with and without Patellofemoral Malalignment:
Basic Science and Treatment
László Hangody and Ivan Udvarhelyi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
13 Autologous Periosteum Transplantation to Treat Full-Thickness
Patellar Cartilage Defects Associated with Severe Anterior
Knee Pain
Håkan Alfredson and Ronny Lorentzon . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
14 Patella Plica Syndrome
Sung-Jae Kim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
15 Patellar Tendinopathy: Where Does the Pain Come From?
Karim M. Khan and Jill L. Cook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
16 Patellar Tendinopathy: The Science Behind Treatment
Karim M. Khan, Jill L. Cook, and Mark A. Young . . . . . . . . . . . . . . . . . . . . . . . . . 269
17 Prevention of Anterior Knee Pain after Anterior Cruciate
Ligament Reconstruction
K. Donald Shelbourne, Scott Lawrance, and Ron Noy . . . . . . . . . . . . . . . . . . . . . . 283
18 Lysis of Pretibial Patellar Tendon Adhesions (Anterior Interval
Release) to Treat Anterior Knee Pain after ACL Reconstruction
Sumant G. Krishnan, J. Richard Steadman, Peter J. Millett,
Kimberly Hydeman, and Matthew Close . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
19 Donor-Site Morbidity after Anterior Cruciate Ligament
Reconstruction Using Autografts
Clinical, Radiographic, Histological, and Ultrastructural Aspects
Jüri Kartus, Tomas Movin, and Jon Karlsson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305

Contents

xv

Section II
Clinical Cases Commented
20 Complicated Case Studies
Roland M. Biedert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
21 Failure of Patellofemoral Surgery: Analysis of Clinical Cases
Robert A. Teitge and Roger Torga-Spak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
22 Arthrofibrosis and Patella Infera
Christopher D. Harner, Tracy M. Vogrin,
and Kenneth J. Westerheide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
23 Neuromatous Knee Pain: Evaluation and Management
Maurice Nahabedian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363
Epilogue
Scott F Dye . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375

Contributors

Håkan Alfredson, MD, PhD
Associate Professor
Umeå University
Sports Medicine Unit
Department of Surgical and
Perioperative Science
Umeå, Sweden
Francisco Aparisi-Rodriguez, MD, PhD
Department of Radiology
Hospital Universitario La Fe
Valencia, Spain
Carlos M. Atienza-Vicente, Mch Eng,
PhD
Orthopaedic Biomechanics Group
Instituto de Biomecánica de Valencia
(IBV)
Universidad Politécnica de Valencia
Valencia, Spain
Kim Bennell, BAppSc(physio), PhD
Centre for Health, Exercise and Sports
Medicine
School of Physiotherapy
Faculty of Medicine, Dentistry and
Health Sciences
University of Melbourne
Australia
Roland M. Biedert, MD
Member of the “International
Patellofemoral Study Group”
Associate Professor, University of Basle
Swiss Federal Institute of Sports
Orthopaedics & Sport Traumatology
Magglingen, Switzerland

Matthew Close, BA
Steadman Hawkins Sports Medicine
Foundation
Vail, Colorado, USA
Jill L. Cook
Musculoskeletal Research Centre
La Trobe University School of
Physiotherapy
Melbourne, Australia
Mario Comín-Clavijo, Mch Eng, PhD
Orthopaedic Biomechanics Group
Instituto de Biomecánica de Valencia
(IBV)
Universidad Politécnica de Valencia
Valencia, Spain
Scott F. Dye, MD
Member of the “International
Patellofemoral Study Group”
Associate Clinical Professor of
Orthopaedic Surgery
University of San Francisco
San Francisco, California, USA
Ejnar Eriksson, MD, PhD
Professor Emeritus of Sports Medicine
Karolinska Institute
Stockholm, Sweden
Donald C. Fithian, MD
Member of the “International
Patellofemoral Study Group”
Kaiser Permanente Medical Group
El Cajon, California, USA

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László Hangody, MD, PhD, DSc
Uzsoki Hospital
Orthopaedic & Trauma Department
Budapest, Hungary
Christopher D. Harner, MD
Medical Director
Center for Sports Medicine
Department of Orthopaedic Surgery
University of Pittsburgh Medical Center
Pittsburgh, PA, USA
Kimberly Hydeman, BA
Steadman Hawkins Sports Medicine
Foundation
Vail, Colorado, USA
Jon Karlsson, MD, PhD
Department of Orthopaedics
Sahlgrenska University Hospital
Göteborg, Sweden
Karim M. Khan
Department of Family Practice & School
of Human Kinetics
University of British Columbia
Vancouver, Canada
Jüri Kartus, MD, PhD
Department of Orthopaedics
NÄL-Hospital
Trollhättan, Sweden
Sung-Jae Kim, MD, PhD, FACS
Arthroscopy and Joint Research Institute
Department of Orthopaedic Surgery
Yonsei University College of Medicine
Seoul, Korea
Sumant G. Krishnan, MD
W.B. Carrell Memorial Clinic
Dallas, Texas, USA
Scott Lawrance, PT, ATC
The Shelbourne Clinic at Methodist
Hospital
Indianapolis, Indiana, USA
Ronny Lorentzon, MD, PhD
Professor
Umeå University
Sports Medicine Unit
Department of Surgical and
Perioperative Science
Umeå, Sweden

Contributors

Vicente Martinez-Sanjuan, MD, PhD
Profesor of Radiology
Universidad Cardenal Herrera
ERESA-Hospital General Universitario
MR and CT Unit
Valencia, Spain
Jenny McConnell, Grad Dip Manip Ther,
MBiomedEng
Centre for Health, Exercise and Sports
Medicine
School of Physiotherapy
Faculty of Medicine, Dentistry and
Health Sciences
University of Melbourne
Australia
McConnell and Clements Physiotherapy
Sydney, Australia
Peter J. Millett, MD, MSc
Harvard Medical School
Brigham & Women’s Hospital
Boston, MA, USA
Eric Montesinos-Berry, MD
Department of Orthopaedics
Hospital Arnau de Vilanova
Valencia, Spain
Carmen Monserrat
Department of Radiology
Hospital Arnau de Vilanova
Valencia, Spain
Tomas Movin, MD, PhD
Department of Orthopaedics
Karolinska University Hospital
Karolinska Institutet
Stockholm, Sweden
Maurice Y. Nahabedian, MD, FACS
Associate Professor of Plastic Surgery
Georgetown University Hospital
Washington, USA
Eiki Nomura, MD
Department Director
Orthopaedic Surgery
Kawasaki Municipal Hospital
Kawasaki, Japan
Ron Noy, MD
The Shelbourne Clinic at Methodist
Hospital
Indianapolis, Indiana, USA

xix

Contributors

Fermín Ordoño, MD, PhD
Department of Neurophysiology
Hospital Arnau de Vilanova
Valencia, Spain

Alfredo Subías-López, MD
Department of Orthopaedics
Hospital Lluís Alcanyís
Játiva, Valencia, Spain

Jaime M. Prat-Pastor, MD, PhD
Orthopaedic Biomechanics Group
Instituto de Biomecánica de Valencia
(IBV)
Universidad Politécnica de Valencia
Valencia, Spain

Robert A. Teitge, MD
Member of the “International
Patellofemoral Study Group”
Department of Orthopaedics
Wayne State University School of
Medicine
Detroit, Michigan, USA

Carlos Puig-Abbs, MD
Orthopaedic Surgeon
Department of Orthopaedics
Hospital Universitario Dr Peset
Valencia, Spain
Fernando Revert-Ros
Patología Molecular
Fundación Valenciana de
Investigaciones Biomédicas
Valencia, Spain
Esther Roselló-Sastre, MD, PhD
Pathologist
Department of Pathology
Hospital Universitario Dr. Peset
Valencia, Spain
Vicente Sanchis-Alfonso, MD, PhD
Member of the International
Patellofemoral Study Group and Member
of the ACL Study Group
Staff Orthopaedic Surgeon
Department of Orthopaedics
Hospital Arnau de Vilanova
Valencia, Spain
Juan Saus-Mas
Patología Molecular
Fundación Valenciana de
Investigaciones Biomédicas
Valencia, Spain
K. Donald Shelbourne, MD
The Shelbourne Clinic at Methodist
Hospital
Indianapolis, Indiana, USA
J. Richard Steadman, MD
Steadman Hawkins Sports Medicine
Foundation
Vail, Colorado, USA

Roger Torga-Spak, MD
Instituto Universitario CEMIC
Buenos Aires, Argentina
Iván Udvarhelyi, MD
Uzsoki Hospital
Orthopaedic & Trauma Department
Budapest, Hungary
Damien Van Tiggelen, PT
Department of Rehabilitation Sciences
and Physical Therapy
Faculty of Medicine
University of Gent
Gent, Belgium
Department of Traumatology and
Rehabilitation
Military Hospital of Base Queen Astrid
Brussels, Belgium
Tracy M. Vogrin
Center for Sports Medicine
Department of Orthopaedic Surgery
University of Pittsburgh Medical
Center
Pittsburgh, PA, USA
Suzanne Werner, PT, PhD
Associated Professor
Dpt Physical Therapy
Karolinska Institutet & Section Sports
Medicine
Karolinska Hospital
Stockholm, Sweden
Kenneth J. Westerheide, MD
Center for Sports Medicine
Department of Orthopaedic Surgery
University of Pittsburgh Medical
Center
Pittsburgh, PA, USA

xx

Tine Willems
Department of Rehabilitation Sciences
and Physical Therapy
Faculty of Medicine
University of Gent
Gent, Belgium
Erik Witvrouw, PT, PhD
Department of Rehabilitation Sciences
and Physical Therapy
Faculty of Medicine
University of Gent
Gent, Belgium

Contributors

Mark A. Young
Musculoskeletal Research Centre
La Trobe University School of
Physiotherapy
Melbourne, Australia

I
Etiopathogenic Bases and Therapeutic Implications

1
Background: Patellofemoral Malalignment versus
Tissue Homeostasis
Myths and Truths about Patellofemoral Disease
Vicente Sanchis-Alfonso

Introduction
Anterior knee paina is the most common knee
complaint seen in adolescents and young adults,
in both the athletic and nonathletic population,
although in the former, its incidence is higher.
The rate is around 9% in young active adults.69
Its incidence is 5.4% of the total injuries and as
high as a quarter of all knee problems treated at
a sports injury clinic.16 Nonetheless, I am convinced that not all cases are diagnosed and hence
the figure is bound to be even higher.
Furthermore, it is to be expected that the number of patients with this complaint will increase
because of the increasing popularity of sport
practice. On the other hand, a better understanding of this pathology by orthopedic surgeons and general practitioners should lead to
this condition being diagnosed more and more
frequently. Females are particularly predisposed
to it.14 Anatomic factors such as increased pelvic
width and resulting excessive lateral thrust on
the patella, and postural and sociological factors
such as wearing high heels and sitting with legs
adducted can influence the incidence and severity of this condition in women.29 Moreover, it is
a nemesis to both the patient and the treating
physician, creating chronic disability, limitation
from participation in sports, sick leave, and generally diminished quality of life.
a

Term that describes pain in which the source is either
within the patellofemoral joint or in the support structures
around it.

Special mention should be made of the term
“patellar tendonitis,” closely related to anterior
knee pain. In 1998, Arthroscopy published an
article by Nicola Maffulli and colleagues52 that
bore the title “Overuse tendon conditions: Time
to change a confusing terminology.” Very aptly,
these authors concluded that the clinical
syndrome characterized by pain (diffuse or
localized), tumefaction, and a lower sports performance should be called “tendinopathy.”52 The
terms tendinitis, paratendinitis, and tendinosis
should be used solely when in possession of the
results of an excision biopsy. Therefore the pervasive clinical diagnosis of patellar tendinitis,
which has become the paradigm of overuse tendon injuries, would be incorrect. Furthermore,
biopsies in these types of pathologies do not
prove the existence of chronic or acute inflammatory infiltrates, which clearly indicate the
presence of tendinitis. Patellar tendinopathy is a
frequent cause for anterior knee pain, which can
turn out to be frustrating for physicians as well
as for athletes, for whom this lesion can well
mean the end of their sports career. This means
that in this monograph we cannot leave out a
discussion of this clinical entity, which is dealt
with in depth in Chapters 15 and 16.
Finally, anterior knee pain is also a welldocumented complication and the most common complaint after anterior cruciate ligament
(ACL) reconstruction. Because of the upsurge
of all kinds of sports, ACL injuries have become
increasingly common and therefore their surgical

3

4

treatment is currently commonplace.b The incidence of anterior knee pain after ACL reconstruction with bone-patellar tendon-bone
(B-PT-B) autografts is from 4% to 40% .24 In this
sense, we must remember that the tissue most
commonly used for ACL reconstruction, according to the last survey of the ACL Study Group
(May 29–June 4, 2004, Forte Village Resort,
Sardinia, Italy), is the B-PT-B.9 Moreover, anterior knee pain is also a common complaint,
from 6% to 12.5% after 2 years, with the use of
hamstring grafts.4,11,48,65 For the reasons mentioned above, we believe it is interesting to carry
out a detailed analysis in this book of the
appearance of anterior knee pain secondary to
ACL reconstructive surgery, underscoring the
importance of treatment, and especially, prevention. In order not to fall into the trap of dogmatism, the problem is analyzed by different
authors from different perspectives (see
Chapters 17 to 19).

The Problem
In spite of its high incidence, anterior knee pain
syndrome is the most neglected, the least
known, and the most problematic pathological
knee condition. This is why the expression
“Black Hole of Orthopedics” that Stanley James
used to refer to this condition is extremely apt to
describe the current situation. On the other
hand, our knowledge of the causative mechanisms of anterior knee pain is limited, with the
consequence that its treatment is one of the
most complex among the different pathologies
of the knee. As occurs with any pathological
condition, and this is not an exception, for the
correct application of conservative as well as
operative therapy, it is essential to have a thorough understanding of the pathogenesis of the
same (see Chapters 2, 3, 4, 8, and 11). This is the
only way to prevent the all-too-frequent stories
of multiple failed surgeries and demoralized
patients, a fact that is relatively common for the
clinical entity under scrutiny in this book as
compared with other pathological processes
affecting the knee (see Chapters 20 and 21).

b

In the general population, an estimated one in 3000 individuals sustains an ACL injury per year in the United
States,37 corresponding to an overall injury rate of approximately 80,00032 to 100,00037 injuries annually. The highest
incidence is in individuals 15 to 25 years old who participate
in pivoting sports.32

Etiopathogenic Bases and Therapeutic Implications

Finally, diagnostic errors, which can lead to
unnecessary interventions, are relatively frequent
in this pathologic condition. As early as 1922, in
the German literature, Georg Axhausen5 stated
that chondromalacia can simulate a meniscal
lesion resulting in the removal of normal menisci.
In this connection, Tapper and Hoover,66 in 1969,
suspected that over 20% of women who did badly
after an open meniscectomy had a patellofemoral
pathology. Likewise, John Insall,41 in 1984, stated
that patellofemoral pathology was the most common cause of meniscectomy failure in young
patients, especially women. Obviously, this failure was a result of an erred diagnosis and, consequently, of a mistakenly indicated surgery. At
present, the problem of diagnostic confusion is
still the order of the day. The following data
reflect this problem. In my surgical series 11% of
patients underwent unnecessary arthroscopic
meniscal surgery, which, far from eradicating the
symptoms, had worsened them. An improvement
was obtained, however, after realignment surgery
of the extensor mechanism. Finally, 10% of
patients in my surgical series were referred to a
psychiatrist by physicians who had previously
been consulted.
The question we ask ourselves is: Why is there
less knowledge about this kind of pathology
than about other knee conditions? According to
the International Patellofemoral Study Group
(IPSG),42 there are several explanations: (1) The
biomechanics of the patellofemoral joint is more
complex than that of other structures in the
knee; (2) the pathology of the patella arouses
less clinical interest than that of the menisci or
the cruciate ligaments; (3) there are various
causes for anterior knee pain; (4) there is often
no correlation between symptoms, physical
findings, and radiological findings; (5) there are
discrepancies regarding what is regarded as
“normal;” and (6) there is widespread terminological confusion (“the Tower of Babel”). As
regards what is considered “normal” or “abnormal” it is interesting to mention the work by
Johnson and colleagues,45 who makes a genderdependent analysis of the clinical assessment of
asymptomatic knees. We discuss some of the
conclusions of this interesting study below.
In 1995, the prevailing confusion led to the
foundation by John Fulkerson of the United
States and Jean-Yves Dupont of France of the
IPSG in order to advance in the knowledge of
the patellofemoral joint disorders by intercultural exchange of information and ideas. The

Background: Patellofemoral Malalignment versus Tissue Homeostasis

condition is of such high complexity that even
within this group there are antagonistic
approaches and theories often holding dogmatic
positions. Moreover, to stimulate research
efforts and education regarding patellofemoral
problems John Fulkerson created in 2003 the
Patellofemoral Foundation. The Patellofemoral
Foundation sponsors the “Patellofemoral
Research Excellence Award” to encourage
outstanding research leading to improved
understanding, prevention, and treatment of
patellofemoral pain or instability. I want to
emphasize the importance to improve prevention and diagnosis in order to reduce the
economic and social costs of this pathology
(see Chapters 6, 8, and 17). Moreover this
foundation sponsors the “Patellofemoral
Traveling Fellowship” to promote better understanding and communication regarding patellofemoral pain, permitting visits to several centers,
worldwide, that offer opportunities to learn
about the complexities of patellofemoral pain.
This chapter provides an overview of the most
important aspects of etiopathogenesis of anterior knee pain and analyzes some myths and
truths about patellofemoral disease.

Historical Background: Internal
Derangement of the Knee and
Chondromalacia Patellae; Actual
Meaning of Patellar Chondral Injury
Anterior knee pain in young patients has historically been associated with the terms “internal
derangement of the knee” and “chondromalacia
patellae.” In 1986, Schutzer and colleagues63 published a paper in the Orthopedic Clinics of North
America about the CT-assisted classification of
patellofemoral pain. The authors of that paper
highlight the lack of knowledge that besets this
clinical entity when they associate the initials of
internal derangement of the knee (IDK) with
those of the phrase “I Don’t Know,” and those of
chondromalacia patellae (CMP) with those of
“Could be – May be – Possibly be.” Although we
think that nowadays this is certainly an exaggeration, it is true that the analogy helps us underscore the controversies around this clinical
entity, or at least draw people’s attention to it.
The expression “internal derangement of the
knee” was coined in 1784 by British surgeon
William Hey.50 This term was later discredited by
the German school surgeon Konrad Büdinger, Dr.
Billroth’s assistant in Vienna, who in 1906

5

described fissuring and degeneration of the patellar articular cartilage of spontaneous origin,7 and
in 1908 in another paper described similar lesions
of traumatic origin.8 Although Büdinger was the
first to describe chondromalacia, this term was
not used by Büdinger himself. Apparently it was
Koenig who in 1924 used the term “chondromalacia patellae” for the first time, although according to Karlson this term had already been used in
Aleman’s clinic since 1917.1,28 What does seem
clear is that it was Koenig who popularized the
term. Büdinger considered that the expression
“internal derangement of the knee” was a
“wastebasket” term. And he was right since the
expression lacks any etiological, therapeutic, or
prognostic implication.
Until the end of the 1960s anterior knee pain
was attributed to chondromalacia patellae.
Stemming from the Greek chondros and malakia,
this term translates literally as “softened patellar
articular cartilage.” However, in spite of the fact
that the term “chondromalacia patellae” has historically been associated with anterior knee pain,
many authors have failed to find a connection
between both.12,49,59 In 1978, Leslie and Bentley
reported that only 51% of patients with a clinical
diagnosis of chondromalacia had changes on the
patellar surface when were examined by
arthroscopy.49 In 1991, Royle and colleagues59
published in Arthroscopy a study in which they
analyzed 500 arthroscopies performed in a 2-year
period, with special reference made to the
patellofemoral joint. In those patients with pain
thought to be arising from this joint, 63% had
“chondromalacia patellae” compared with a 45%
incidence in those with meniscal pathological
findings at arthroscopy. They concluded that
patients with anterior knee pain do not always
have patellar articular changes, and patellar
pathology is often asymptomatic (Figure 1.1).
In agreement with this, Dye18 did not feel any
pain during arthroscopic palpation of his extensive lesion of the patellar cartilage without
intraarticular anesthesia. In this regard it would
be remembered that the articular cartilage is
devoid of nerve fibers and, therefore, cannot hurt.
Surgeons often refer to patellar cartilage
changes as chondromalacia, using poor defined
grades. According to the IPSG42 we should use the
term chondral or cartilage lesion, and rather than
resorting to grades in a classification, providing a
clear description of the injury (e.g., appearance,
depth, size, location, acute vs. chronic clinical status). Although hyaline cartilage cannot be the

6

Etiopathogenic Bases and Therapeutic Implications

irrelevant. In short, chrondromalacia patellae is
not synonymous with patellofemoral pain.
Thus, the term chondromalacia, is also, using
Büdinger’s own words, a wastebasket term as it
is lacking in practical utility. In this way, the following ominous 1908 comment from Büdinger
about “internal derangement of the knee” could
be applied to chondromalacia:22 “[It] will simply
not disappear from the surgical literature. It is
the symbol of our helplessness in regards to a
diagnosis and our ignorance of the pathology.”
Although I am aware of the fact that traditions
die hard, the term “chondromalacia patellae”
should be excluded from the clinical terminology of current orthopedics for the reasons I have
expressed. Almost one century has elapsed and
this term is still used today, at least in Spain, by
clinicians, by the staff in charge of codifying the
different pathologies for our hospitals’ databases, as well as by private health insurers’ lists
of covered services.

Patellofemoral Malalignment
In the 1970s anterior knee pain was related to the
presence of patellofemoral malalignment (PFM).c
In 1968, Jack C. Hughston (Figure 1.2) published
an article on subluxation of the patella, which
represented a major turning point in the recognition and treatment of patellofemoral disorders.35
In 1974, Al Merchant, in an attempt to better
understand patellofemoral biomechanics, introFigure 1.1. The intensity of preoperative pain is not related to the seriousness or the extension of the chondromalacia patellae found during
surgery. The most serious cases of chondromalacia arise in patients with
a recurrent patellar dislocation who feel little or no pain between their
dislocation episodes (a). Chondral lesion of the patella with fragmentation and fissuring of the cartilage in a patient with PFM that consulted for
anterior knee pain (b).

source of pain in itself, damage of articular cartilage can lead to excessive loading of the subchondral bone, which, due to its rich innervation,
could be a potential source of pain. Therefore, a
possible indication for very selected cases could
be a resurfacing procedure such as mosaicplasty
(see Chapter 12) or periostic autologous transplants (see Chapter 13).
According to the IPSG,42 the term chondromalacia should not be used to describe a clinical
condition; it is merely a descriptive term for
morphologic softening of the patellar articular
cartilage. In conclusion, this is a diagnosis that
can be made only with visual inspection and palpation by open or arthroscopic means and it is

Figure 1.2. Jack C. Hughston, MD (1917–2004). One of the founding
fathers of Sports Medicine. (Reproduced with permission from the Journal of
Athletic Training, 2004; 39: 309.)

c

We define PFM as an abnormality of patellar tracking that
involves lateral displacement or lateral tilt of the patella, or
both, in extension, that reduces in flexion.

7

Background: Patellofemoral Malalignment versus Tissue Homeostasis

duced the axial radiograph of the patellofemoral
joint.54 The same author suggested, also in 1974,
the lateral retinacular release as a way of treating
recurrent patellar subluxation.55 In 1975, Paul
Ficat, from France, popularized the concept of
patellar tilt, always associated with increased
tightness of the lateral retinaculum, which caused
excessive pressure on the lateral facet of the
patella, leading to the “lateral patellar compression syndrome” (“Syndrome d’Hyperpression
Externe de la Rotule”).21 According to Ficat lateral
patellar compression syndrome would cause
hyperpressure in the lateral patellofemoral compartment and hypopressure in the medial
patellofemoral compartment. Hypopressure and
the disuse of the medial patellar facet would cause
malnutrition and early degenerative changes in
the articular cartilage because of the lack of normal pressure and function. This may explain why
early chondromalacia patellae is generally found
in the medial patellar facet. Hyperpression also
would favor cartilage degeneration, which might
explain the injury of the lateral facet. Two years
later, in 1977, Ficat and Hungerford22 published
Disorders of the Patellofemoral Joint, a classic of
knee extensor mechanism surgery and the first
book in English devoted exclusively to the extensor mechanism of the knee. In the preface of the
book these authors refer to the patellofemoral
joint as “the forgotten compartment of the knee.”
This shows what the state of affairs was in those
days. In fact, before the 1970s only two diagnoses
were used relating to anterior knee pain or patellar instability: chondromalacia patellae and
recurrent dislocation of the patella. What is more,
the initial designs for knee arthroplasties ignored
the patellofemoral joint. In 1979, John Insall published a paper on “patellar malalignment syndrome”38 and his technique for proximal patellar
realignment, used to treat this syndrome.39
According to Insall lateral loading of the patella is
increased in malalignment syndrome. In some
cases, this causes chondromalacia patellae, but it
does not necessarily mean that chondromalacia is
the cause of pain.41 In this way, in 1983 Insall and
colleagues reported that anterior knee pain correlates better to malalignment rather than with the
severity of chondromalacia found during surgery.40 Fulkerson and colleagues have also
emphasized the importance of PFM and excessively tight lateral retinaculum as a source of
anterior knee pain.25,26,63 Finally, in 2000, Ronald
Grelsamer,31 from the IPSG, stated that malalignment appears to be a necessary but not sufficient

condition for the onset of anterior knee pain.d
According to Grelsamer,31 pain seems to be set
off by a trigger (i.e., traumatism). In this sense,
Grelsamer30 tells his patients that “people with
malaligned knees are akin to someone riding a
bicycle on the edge of a cliff. All is well until
a strong wind blows them off the cliff, which may
or may not ever happen.” Although it is more
common to use the term malalignment as a malposition of the patella on the femur some authors,
as Robert A Teitge, from the IPSG, use the term
malalignment as a malposition of the knee joint
between the body and the foot with the subsequent effect on the patellofemoral mechanics (see
Chapter 11).
In a previous paper61 we postulated that PFM,
in some patients with patellofemoral pain, produces a favorable environment for the onset of
symptoms, and neural damage would be the
main “provoking factor” or “triggering factor.”
Overload or overuse may be another triggering
factor. In this sense, in our surgical experience,
we have found that in patients with symptoms in
both knees, when the more symptomatic knee is
operated on, the symptoms in the contralateral
less symptomatic malaligned knee disappear or
decrease in many cases, perhaps because we have
reduced the load in this knee; that is, it allows us
to restore joint homeostasis. In this connection,
Thomee and colleagues suggested that chronic
overloading and temporary overuse of the
patellofemoral joint, rather than malalignment,
contribute to patellofemoral pain.68
For many years, PFM has been widely
accepted as an explanation for the genesis of
anterior knee pain and patellar instability in the
young patient. Moreover, this theory had a great
influence on orthopedic surgeons, who developed several surgical procedures to “correct the
malalignment.” Unfortunately, when PFM was
diagnosed it was treated too often by means of
surgery. A large amount of surgical treatments
has been described, yielding extremely variable
results. Currently, however, the PFM concept is
questioned by many, and is not universally
accepted to account for the presence of anterior
knee pain and/or patellar instability.

d

However, many patients with patellofemoral pain have no
evidence of malalignment, whatsoever.68 Therefore if PFM is
a necessary condition for the presence of patellofemoral
pain, how could patellofemoral pain be occurring in patients
without malalignment?

8

At present, most of the authors agree that
only a small percentage of patients with
patellofemoral pain have truly malalignment
and are candidates for surgical correction of
malalignment for resolution of symptoms. In
fact, the number of realignment surgeries has
dropped dramatically in recent years, due to
a reassessment of the paradigm of PFM.
Moreover, we know that such procedures are,
in many cases, unpredictable and even dangerous; they may lead to reflex sympathetic dystrophy, medial patellar dislocations, and
iatrogenous osteoarthrosis (see Chapters 20
and 21). We should recall here a phrase by doctor Jack Hughston, who said: “There is no
problem that cannot be made worse by surgery” (see Chapters 20 to 23). Among problems
with the knee, this statement has never been
more relevant than when approaching the
extensor mechanism. Therefore, we must
emphasize the importance of a correct diagnosis (see Chapters 6 and 7) and nonoperative
treatment (see Chapters 9 and 10).

Etiopathogenic Bases and Therapeutic Implications

patients with normal patellofemoral alignment
on computed tomography (CT) can also suffer
from anterior knee pain (Figure 1.4). Therefore,
PFM cannot explain all the cases of anterior knee
pain, so other pathophysiological processes must
exist. Moreover, PFM theory cannot adequately
explain the variability of symptoms experienced
by patients with anterior knee pain syndrome.
Finally, we must also remember that it has been
demonstrated that there are significant differences between subchondral bone morphology
and geometry of the articular cartilage surface of
the patellofemoral joint, both in the axial and
sagittal planes6 (Figure 1.5). Therefore, a radiographical PFM may not be real and it could
induce us to indicate a realignment surgery than
could provoke involuntarily an iatrogenic PFM
leading to a worsening of preoperative symptoms.
This would be another point against the universal
acceptance of the PFM theory. Moreover, this
could explain also the lack of predictability of
operative results of realignment surgery.

Critical Analysis of Long-term Follow-up
The great problem of the PFM concept is that not of Insall’s Proximal Realignment for
all malalignments, even of significant propor- PFM: What Have We Learned?
Criticism

tions, are symptomatic. Even more, one knee
may be symptomatic and the other not, even
though the underlying malalignment is entirely
symmetrical (Figure 1.3). On the other hand,

In agreement with W.S. Halsted, I think that the
operating room is “a laboratory of the highest
order.” As occurs with many surgical techniques,
and realignment surgery is not an exception,

Figure 1.3. CT at 0° from a patient with anterior knee pain and functional patellofemoral instability in the right knee; however, the left knee is
completely asymptomatic. In both knees the PFM is symmetric.

Background: Patellofemoral Malalignment versus Tissue Homeostasis

9

Figure 1.4. CT at 0° from a patient with severe anterior knee pain and patellofemoral instability in the left knee (a). This knee, which was operated
on two years ago, performing an Insall’s proximal realignment, was very symptomatic in spite of the correct patellofemoral congruence. Fulkerson
test for medial subluxation was positive. Nevertheless, the right knee was asymptomatic despite the PFM. Conventional radiographs were normal
and the patella was seen well centered in the axial view of Merchant (b). Axial stress radiograph of the left knee (c) allowed us to detect an iatrogenic medial subluxation of the patella (medial displacement of 15 mm). Note axial stress radiograph of the right knee (d). The symptomatology
disappeared after surgical correction of medial subluxation of the patella using iliotibial tract and patellar tendon for repairing the lateral stabilizers of the patella.

10

Etiopathogenic Bases and Therapeutic Implications

Figure 1.5. Scheme of gadolinium-enhanced MR arthrotomogram of the left knee in the axial plane. Note perfect patellofemoral congruence (a).
Note patellofemoral incongruence of the osseous contours (b). (Reprinted from Clin Sports Med, 21, HU Staeubli, C Bosshard, P Porcellini, et al.,
Magnetic resonance imaging for articular cartilage: Cartilage-bone mismatch, pp. 417–433, 2002, with permission from Elsevier.)

after wide usage, surgeons may question the
basic tenets and may devise clinical research to
test the underlying hypothesis, in our case the
PFM concept.
In this way we have evaluated retrospectively
40 Insall’s proximal realignments (IPR) performed on 29 patients with isolated symptomatic PFM.e The average follow-up after surgery
was 8 years (range 5–13 years). The whole study
is p